// Copyright (C) 2024 EA group inc.
// Author: Jeff.li lijippy@163.com
// All rights reserved.
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published
// by the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <https://www.gnu.org/licenses/>.
//

#include <turbo/hash/internal/murmur3.h>
#include <turbo/base/attributes.h>

namespace turbo::hash_internal {


    static TURBO_ATTRIBUTE_ALWAYS_INLINE uint32_t rotl32(uint32_t x, int8_t r) { return (x << r) | (x >> (32 - r)); }

    static TURBO_ATTRIBUTE_ALWAYS_INLINE uint64_t rotl64(uint64_t x, int8_t r) { return (x << r) | (x >> (64 - r)); }

#define ROTL32(x, y) rotl32(x, y)
#define ROTL64(x, y) rotl64(x, y)

#define BIG_CONSTANT(x) (x##LLU)

//-----------------------------------------------------------------------------
// Block read - if your platform needs to do endian-swapping or can only
// handle aligned reads, do the conversion here

#define getblock(p, i) (p[i])

    //-----------------------------------------------------------------------------
    // Finalization mix - force all bits of a hash block to avalanche

    static TURBO_ATTRIBUTE_ALWAYS_INLINE uint32_t fmix32(uint32_t h) {
        h ^= h >> 16;
        h *= 0x85ebca6b;
        h ^= h >> 13;
        h *= 0xc2b2ae35;
        h ^= h >> 16;

        return h;
    }


    static TURBO_ATTRIBUTE_ALWAYS_INLINE uint64_t fmix64(uint64_t k) {
        k ^= k >> 33;
        k *= BIG_CONSTANT(0xff51afd7ed558ccd);
        k ^= k >> 33;
        k *= BIG_CONSTANT(0xc4ceb9fe1a85ec53);
        k ^= k >> 33;

        return k;
    }


    void MurmurHash3_x86_32(const void *key, int len, uint32_t seed, void *out) {
        const uint8_t *data = (const uint8_t *) key;
        const int nblocks = len / 4;
        int i;

        uint32_t h1 = seed;

        uint32_t c1 = 0xcc9e2d51;
        uint32_t c2 = 0x1b873593;

        //----------
        // body

        const uint32_t *blocks = (const uint32_t *) (data + nblocks * 4);

        for (i = -nblocks; i; i++) {
            uint32_t k1 = getblock(blocks, i);

            k1 *= c1;
            k1 = ROTL32(k1, 15);
            k1 *= c2;

            h1 ^= k1;
            h1 = ROTL32(h1, 13);
            h1 = h1 * 5 + 0xe6546b64;
        }

        //----------
        // tail

        const uint8_t *tail = (const uint8_t *) (data + nblocks * 4);

        uint32_t k1 = 0;

        switch (len & 3) {
            case 3:
                k1 ^= tail[2] << 16;
            case 2:
                k1 ^= tail[1] << 8;
            case 1:
                k1 ^= tail[0];
                k1 *= c1;
                k1 = ROTL32(k1, 15);
                k1 *= c2;
                h1 ^= k1;
        };

        //----------
        // finalization

        h1 ^= len;

        h1 = fmix32(h1);

        *(uint32_t *) out = h1;
    }

//-----------------------------------------------------------------------------

    void MurmurHash3_x86_128(const void *key, const int len, uint32_t seed, void *out) {
        const uint8_t *data = (const uint8_t *) key;
        const int nblocks = len / 16;
        int i;

        uint32_t h1 = seed;
        uint32_t h2 = seed;
        uint32_t h3 = seed;
        uint32_t h4 = seed;

        uint32_t c1 = 0x239b961b;
        uint32_t c2 = 0xab0e9789;
        uint32_t c3 = 0x38b34ae5;
        uint32_t c4 = 0xa1e38b93;

        //----------
        // body

        const uint32_t *blocks = (const uint32_t *) (data + nblocks * 16);

        for (i = -nblocks; i; i++) {
            uint32_t k1 = getblock(blocks, i * 4 + 0);
            uint32_t k2 = getblock(blocks, i * 4 + 1);
            uint32_t k3 = getblock(blocks, i * 4 + 2);
            uint32_t k4 = getblock(blocks, i * 4 + 3);

            k1 *= c1;
            k1 = ROTL32(k1, 15);
            k1 *= c2;
            h1 ^= k1;

            h1 = ROTL32(h1, 19);
            h1 += h2;
            h1 = h1 * 5 + 0x561ccd1b;

            k2 *= c2;
            k2 = ROTL32(k2, 16);
            k2 *= c3;
            h2 ^= k2;

            h2 = ROTL32(h2, 17);
            h2 += h3;
            h2 = h2 * 5 + 0x0bcaa747;

            k3 *= c3;
            k3 = ROTL32(k3, 17);
            k3 *= c4;
            h3 ^= k3;

            h3 = ROTL32(h3, 15);
            h3 += h4;
            h3 = h3 * 5 + 0x96cd1c35;

            k4 *= c4;
            k4 = ROTL32(k4, 18);
            k4 *= c1;
            h4 ^= k4;

            h4 = ROTL32(h4, 13);
            h4 += h1;
            h4 = h4 * 5 + 0x32ac3b17;
        }

        //----------
        // tail

        const uint8_t *tail = (const uint8_t *) (data + nblocks * 16);

        uint32_t k1 = 0;
        uint32_t k2 = 0;
        uint32_t k3 = 0;
        uint32_t k4 = 0;

        switch (len & 15) {
            case 15:
                k4 ^= tail[14] << 16;
            case 14:
                k4 ^= tail[13] << 8;
            case 13:
                k4 ^= tail[12] << 0;
                k4 *= c4;
                k4 = ROTL32(k4, 18);
                k4 *= c1;
                h4 ^= k4;

            case 12:
                k3 ^= tail[11] << 24;
            case 11:
                k3 ^= tail[10] << 16;
            case 10:
                k3 ^= tail[9] << 8;
            case 9:
                k3 ^= tail[8] << 0;
                k3 *= c3;
                k3 = ROTL32(k3, 17);
                k3 *= c4;
                h3 ^= k3;

            case 8:
                k2 ^= tail[7] << 24;
            case 7:
                k2 ^= tail[6] << 16;
            case 6:
                k2 ^= tail[5] << 8;
            case 5:
                k2 ^= tail[4] << 0;
                k2 *= c2;
                k2 = ROTL32(k2, 16);
                k2 *= c3;
                h2 ^= k2;

            case 4:
                k1 ^= tail[3] << 24;
            case 3:
                k1 ^= tail[2] << 16;
            case 2:
                k1 ^= tail[1] << 8;
            case 1:
                k1 ^= tail[0] << 0;
                k1 *= c1;
                k1 = ROTL32(k1, 15);
                k1 *= c2;
                h1 ^= k1;
        };

        //----------
        // finalization

        h1 ^= len;
        h2 ^= len;
        h3 ^= len;
        h4 ^= len;

        h1 += h2;
        h1 += h3;
        h1 += h4;
        h2 += h1;
        h3 += h1;
        h4 += h1;

        h1 = fmix32(h1);
        h2 = fmix32(h2);
        h3 = fmix32(h3);
        h4 = fmix32(h4);

        h1 += h2;
        h1 += h3;
        h1 += h4;
        h2 += h1;
        h3 += h1;
        h4 += h1;

        ((uint32_t *) out)[0] = h1;
        ((uint32_t *) out)[1] = h2;
        ((uint32_t *) out)[2] = h3;
        ((uint32_t *) out)[3] = h4;
    }

//-----------------------------------------------------------------------------

    void MurmurHash3_x64_128(const void *key, const int len, const uint32_t seed, void *out) {
        const uint8_t *data = (const uint8_t *) key;
        const int nblocks = len / 16;
        int i;

        uint64_t h1 = seed;
        uint64_t h2 = seed;

        uint64_t c1 = BIG_CONSTANT(0x87c37b91114253d5);
        uint64_t c2 = BIG_CONSTANT(0x4cf5ad432745937f);

        //----------
        // body

        const uint64_t *blocks = (const uint64_t *) (data);

        for (i = 0; i < nblocks; i++) {
            uint64_t k1 = getblock(blocks, i * 2 + 0);
            uint64_t k2 = getblock(blocks, i * 2 + 1);

            k1 *= c1;
            k1 = ROTL64(k1, 31);
            k1 *= c2;
            h1 ^= k1;

            h1 = ROTL64(h1, 27);
            h1 += h2;
            h1 = h1 * 5 + 0x52dce729;

            k2 *= c2;
            k2 = ROTL64(k2, 33);
            k2 *= c1;
            h2 ^= k2;

            h2 = ROTL64(h2, 31);
            h2 += h1;
            h2 = h2 * 5 + 0x38495ab5;
        }

        //----------
        // tail

        const uint8_t *tail = (const uint8_t *) (data + nblocks * 16);

        uint64_t k1 = 0;
        uint64_t k2 = 0;

        switch (len & 15) {
            case 15:
                k2 ^= (uint64_t) (tail[14]) << 48;
            case 14:
                k2 ^= (uint64_t) (tail[13]) << 40;
            case 13:
                k2 ^= (uint64_t) (tail[12]) << 32;
            case 12:
                k2 ^= (uint64_t) (tail[11]) << 24;
            case 11:
                k2 ^= (uint64_t) (tail[10]) << 16;
            case 10:
                k2 ^= (uint64_t) (tail[9]) << 8;
            case 9:
                k2 ^= (uint64_t) (tail[8]) << 0;
                k2 *= c2;
                k2 = ROTL64(k2, 33);
                k2 *= c1;
                h2 ^= k2;

            case 8:
                k1 ^= (uint64_t) (tail[7]) << 56;
            case 7:
                k1 ^= (uint64_t) (tail[6]) << 48;
            case 6:
                k1 ^= (uint64_t) (tail[5]) << 40;
            case 5:
                k1 ^= (uint64_t) (tail[4]) << 32;
            case 4:
                k1 ^= (uint64_t) (tail[3]) << 24;
            case 3:
                k1 ^= (uint64_t) (tail[2]) << 16;
            case 2:
                k1 ^= (uint64_t) (tail[1]) << 8;
            case 1:
                k1 ^= (uint64_t) (tail[0]) << 0;
                k1 *= c1;
                k1 = ROTL64(k1, 31);
                k1 *= c2;
                h1 ^= k1;
        };

        //----------
        // finalization

        h1 ^= len;
        h2 ^= len;

        h1 += h2;
        h2 += h1;

        h1 = fmix64(h1);
        h2 = fmix64(h2);

        h1 += h2;
        h2 += h1;

        ((uint64_t *) out)[0] = h1;
        ((uint64_t *) out)[1] = h2;
    }

}  // namespace turbo::hash_internal
